Bao G.,MOE Key Laboratory of Advanced Micro Structure Materials |
Bao G.,Tongji University |
Jiao H.,MOE Key Laboratory of Advanced Micro Structure Materials |
Jiao H.,Tongji University |
And 5 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2014
Short-wave pass filter is an important optical component in high power laser systems which has the repetitive structure of (0.5LH0.5L)N. But its optical property is significantly influenced by the half-wave hole due to layer inhomogeneity. Analysis by admittance theory shows the key reason for the presence of half-wave hole: the end point of the admittance locus of the periodic structure based on the quarter-wave stack doesn't return to the initial point again. The greater the deviation, the worse the half-wave hole. By inserting matching layers between high and low index materials, a new method is presented to eliminate half-wave hole. The new short-pass film is designed and successfully fabricated, which has a super wide and smooth region with low reflectance at around second harmonic.The experimental results consistent well with the theoretical performance. Source